- You might clench or grind your teeth,
- Tightening your jaw muscles and stressing your TM joint.
- Damaged jaw joint due to injury or disease.

TMJ stands for Temporo mandibular Joint, which is the name for each joint (right and left) that connects your jaw to your skull. TMJ (temporo mandibular joint) disorders are a family of problems related to your complex jaw joint.
Since some types of TMJ problems can lead to more serious conditions, early detection and treatment are important. If your have had symptoms like pain or a "clicking" sound, these problems are more easily diagnosed and treated that they were in the past. These symptoms occur when the joints of the jaw and the chewing muscles (muscles of mastication) do not work together correctly.
TMJ disorders develop for many reasons
Injuries and arthritis can damage the joint directly or stretch or tear the muscle ligaments. As a result, the disk, which is made of cartilage and functions as the "cushion" for the jaw joint, can slip out of position. Whatever the cause, the results may include a misaligned bite, pain, clicking or grating noise when you open your mouth or trouble opening your mouth wide.